Simplifying the CORAYVAC Commissioning Process

Upon arriving on the job site, take your project heating system drawing and make sure that the installing contractor followed the drawing. From the floor, do a visual inspection of the entire heating system checking that the flex gas lines and all burners are installed per the Installation, Operation and Service Manual. 

Make sure the following items are installed correctly - Hangars, Reflector Supports, Reflectors. Also, make sure radiant and tailpipe tubes are installed at the proper pitch per the Installation, Operation and Service Manual. Move on to the next step after properly installing the equipment. 

Roberts Gordon offers several types of CoRayVac® Heating controllers, as well as modulating controllers. Today, we will install the CoRayVac Modulating Heating Controller. The first thing to do when opening the control panel is to make sure all wires in the panel are connected to terminals and there are none hanging. Check all wires at the terminals ensuring that they are secure and will not come off. Make sure the installing contractor, has zoned the burners based on the drawing. Up to four zones can be used on each control panel. Check to make sure the wire connections to the zone relays, burners and one thermostat per each zone is correct. Ensure the wiring for the pressure switch at the vacuum pump is connected to the correct terminals. Make sure all grounds are connected and secure in the control panel. When all the wiring in the control panel is in place and correct, you are ready to power up the control panel. 

Have the electrician turn on the breaker to the control panel. Test this by using a volt meter, making sure you have 120VAC on the incoming terminals. Turn the zone thermostat, within a few seconds the vacuum pump will start. When you hear the vacuum pump start, turn the thermostat down. When you turn the thermostat down, the pump slows down. Wait until it slows enough to see the shaft turning, then determine the direction of the rotation making sure the motor rotation is turning in the direction of the arrow on the side of the pump. If the rotation of the motor is not in the direction of the arrow on the side of the pump, follow the manufacturers instructions on the rating plate for reverse rotation. 

Part of the commissioning is to ensure that the system vacuum is set properly. Vacuum should be 2.5" negative pressure after the system has operated for twenty to twenty-five minutes. To adjust the vacuum to negative 2.5" to 3.0" water column, adjust the damper on the inlet of the vacuum pump. Opening the damper increases the vacuum and closing the damper, decreases the vacuum. When the system is symmetrical, all branches are the same length. When you have a system that has different length branches, first adjust vacuum using the damper on the inlet of the vacuum pump as in the previous step. After the longer branch is adjusted to 2.5" to 3.0" water column, locate the damper coupling at the tee leading from the shorter branch. Now adjust the vacuum on the shorter branch by opening or closing this damper to achieve the negative 2.5" to 3.0" water column. This concludes the CoRayVac Start-up Instructions.

If you require additional support, please contact your local Roberts Gordon representative or Roberts Gordon at 1-800-828-7450 or online at www.robertsgordon.com. Work must be performed by a qualified contractor.